How Overweight & Obesity Cause Diabetes?

Introduction

Do you know that more than 70% of diabetics in Malaysia are obese? Obesity and Diabetes Mellitus (DM) link to each other as a condition known as Metabolic Syndrome. It is also associated with :

• hyperlipidaemia
• high blood pressure.

As the number of people with obesity increases, the number of people with DM increases as well.

How to measure obesity ?

You can measure obesity by a body mass index (BMI) calculation. It is calculated by dividing your weight in kilograms (kg) by your height in meters (m) squared.

BMI = body weight (kg) / height  X  height  (m²)

You can also measure waist circumference to determine abdominal obesity. It is positive when the waist circumference is above 90 cm in man or above 80 cm in woman.

Figure 1 : Waist circumference measurement (http://www.virtualmedicalcentre.com)

How to interpret BMI ?

BMI	You are
Less than 18.5	Underweight
18.5—22.9	Ideal weight
More than 23	Overweight
23-27.4	Pre-obese
More than 27.5	Obese

 

Why is obesity associated with DM?

If you are obese and having other risk factors for DM, your muscle and fat cells may not use the insulin efficiently, the term known as insulin resistance.

Your pancreas has to secrete more insulin to overcome this insulin resistance, in order to maintain normal blood glucose.

In long term, your pancreas will be overworked and finally FAIL to secrete enough insulin. As a result of this, your blood glucose may be abnormal from pre-DM stage to frank type 2 DM

Figure 2 : Mechanisms for insulin resistance and DM development (Nature 444, 840-846 (14 December 2006) )

 

What are insulin resistance signs ?

If you have insulin resistance, you are likely obese and frequently has skin pigmentation known as acanthosis nigricans.

The pigmentation can be seen in the :

1. neck
2. arm pit, or
3. knuckle

You may have :

1. high blood pressure
2. abnormal blood lipids.

Figure 3 : Acanthosis nigricans   (Art Huntley, Rhett Drugge: Electronic textbook of dermatology).

 

What can I do to improve insulin resistance ?

Losing as little as 5 to 10% of your weight can reduce :

1. insulin resistance, and
2. your risk for DM.

You also need to :

1. increase physical activity
2. quit smoking
3. eating healthy food.

It can help you to :

• reduce your blood pressure
• improve your cholesterol and blood sugar levels.

 

References

1. Five Stages of Evolving Beta-Cell Dysfunction During Progression to Diabetes Gordon CW, Susan BW. Diabetes, Dec2004 vol. 53 no. suppl 3 S16-S21.
2. The IDF consensus worldwide definition of the metabolic syndrome [online]. Brussels, Belgium: International Diabetes Federation. 8 March 2007.
3. Mafauzy M, Current Medical Research and Opinion. 24 (2 ) 2008.